This clarifies what parts of the router are specific to the binlogrouter
and what are common between the binlogrouter and avrorouter.
Ideally, the two modules would use the same infrastructure to handle the
processing of replication events. This is the first, albeit small, step
towards making the code in the binlogrouter the common infrastructure.
According to customer reports collecting the statistics has a significant
impact on the performance. As we don't need that information we can just
as well turn off that.
Further, since maxscale-common now links to the sqlite3-library, no
module needs to do that explicitly.
